关键词: 扩底桩, 模型试验, 桩端, 承载力, 桩端承载机制

Abstract: The bearing capacity of pile tip is the main component of the pedestal pile; so it is the key of the pedestal pile design that how to evaluate the bearing mechanism qualitatively and quantitavely. By the model test of pedestal pile, we’ve done some discussion and analysis of the pile-tip bearing mechanism of the pedestal pile, and drawn some conclusion as follows. The value of the pedestal pile bearing capacity is determined by the exerting level of the pile-tip bearing capacity. The unsynchronized level of the pile-tip bearing capacity and shaft resistance of pedestal pile is much more obvious than that of the non-pedestal pile. The limit equilibrium zone of the pedestal pile tip is different from that of the non-pedestal pile tip; but is similar to that of contrary anchor-slab foundation. Because of the enlarged part, the foundation bearing capacity at pile tip is lower in some extent; so during the design and calculation of the pedestal pile tip bearing capacity, it is necessary to modify the pile tip bearing capacity lowered by the enlarged bottom.

Key words: pedestal pile, model test, pile tip, bearing capacity, pile-tip bearing mechanism